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Choi, Jong Lak;Yoon, Shin Sook;Chun, Keun Ho;Nam Shin, Jeong E.
- Journal of the Korean Chemical Society
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- v.42 no.1
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- pp.78-83
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- 1998
It's necessary to develope a facile methodology forming ${\alpha}$-altropyranosidic linkage, for the synthesis of trisaccharide repeating unit of O-antigenic part of Campylobacter jejuni gram negative bacteria. In this paper, the effective synthesis of disaccharides containing ${\alpha}$-altropyranosidic linkage by 1,2-trans glycosidation of allal derivatives was discussed. 4, 6-O-Benzylidene-3-O-(t-butyldimethylsilyl)-D-allal was treated with DMDO (3,3-dimethy ldioxirane) to yield 1,2-anhydro-4, 6-O-benzylidene-3-O-(t-butyldimethylsilyl)-${\beta}$-D-altropyranose. The reaction of 1,2-anhydro-4, 6-O-benzylidene-3-O-(t-butyldimethylsilyl)-${\beta}$-D-altropyranose with allyl alcohol gave allyl 4, 6-O-benzylidene-3-(t-butyldimethylsilyl)-${\alpha}$-D-altropyranoside quantitatively, and reactions with glucals were also successful to prepare ${\alpha}$-altropyranosodic disaccharides. It is convinced that 1,2-trans glycosidation of allal derivatives should be an attractive choice for preparing oligosaccharides containing ${\alpha}$-altropyranosidic linkages.
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Lim, Woo-Seok;Lee, Jae-Won
- Journal of the Korean Wood Science and Technology
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- v.40 no.4
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- pp.294-301
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- 2012
In this study, we investigated the features of bioethanol fermentation of corncob biomass after oxalic acid pretreatment as well as enzymatic hydrolysis. The enzymatic hydrolysis was performed with Accellerase 1000 and the highest yield of monomeric sugars ($64.8g/{\ell}$) was obtained at $50^{\circ}C$ and pH 4.5 for 96 hrs hydrolysis period. For the ethanol fermentation the monomeric sugars obtained from pretreated corncob were subjected to the biological treatment using Pichia stipitis CBS 6054. It was turned out that ethanol production from oxalic acid pretreated corncob was the most feasible at 10~14% of biomass loading as well as 15 FPU enzyme amount. Under these fermentation condition, the ethanol yield was approached to 0.47 after 24 hrs fermentation period, which was corresponded to 92.2% of conversion rate.
https://doi.org/10.5658/WOOD.2012.40.4.294 인용 PDF KSCI

Park, Seok-Cheol
- Journal of Food Hygiene and Safety
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- v.15 no.3
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- pp.199-203
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- 2000
With a rabbit model, the present study was performed to examine the effect of Escherichia coli lipopolysaccharide (E. coli LPS) on hormones. Cortisol, epinephrine, and norepinephrine concentrations in LPS-treated groups were high at all sampling periods (from 3 hrs to 72 hrs) as compared to control group (p<0.05 or p<0.01). The each peak time was at respectively 24 hrs, 3 hrs, and 12 hrs. Insulin and glucagon concentrations in LPS-treated groups elevated up to 12 hrs (p<0.01 or p<0.05) with a each peak point at 12 hrs or 6 ks, while those of the rest sampling points (from 24 hrs to 72 hrs) were lower than that of control (p<0.05). Increase of cortisol concentration was generally dose-dependent, whereas the changes of the other hormones were irregular patterns. These observations show that E. coli LPS lead to releases of stress hormones such as cortisol, epinephrine, and norepinephrine and disturbances of endocrine systems. These LPS-induced hormonal disorders may cause physiologically fatal results.
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Chang, Sang-Moon;Shin, Young-Bum;Choi, Jyung
- Korean Journal of Soil Science and Fertilizer
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- v.23 no.2
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- pp.135-139
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- 1990
This study was carried out to find favourable soil conditions to give quality of Astragali Radix. Plants were grown in the soils of different physico-chemical properties, and ash, ethanol extract and free sugars from their roots were analyzed. Fructose and sucrose extracted from the root were determined by HPLC. The contents of Fe were 6.2~7.6 ppm. The ash contents of the root were positively correlated with the available $P_2O_5$ in the soils as well as P and K in the root.
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